The present invention relates to the field of occupational and traffic safety, specifically for the transportation and construction industries. More specifically, the present invention relates to safety at roadway work sites where repair and/or new construction work is undertaken in close proximity to vehicular traffic.
Where repair and/or construction work is performed on or adjacent a portion of a busy roadway, it may be deemed preferable from a safety standpoint to simply close that portion of roadway to entirely eliminate the possibility of accidents occurring that involve roadway vehicles, construction vehicles, construction machinery and/or construction workers. Unfortunately, closing a portion of roadway is often deemed to be impractical and/or impossible—with the result that construction work must be undertaken on or adjacent to a portion of roadway where there is still vehicular traffic. As is well known to those skilled in the art, this opens the door to instances in which vehicular traffic may collide with construction vehicles, construction equipment and/or construction personnel as a result of impatient, distracted, sleep-deprived, intoxicated and/or otherwise impaired motorists who drive near to and alongside roadway work sites.
Various prior art measures have been undertaken to at least mitigate the resulting dangers of injury and death to construction workers, including and not limited to, scheduling repair and/or construction work during nights or during other hours when there is reduced vehicular traffic, reduced work site speed limits accompanied by increased fines for violators, brightly colored work zone warning signage and/or flashing warning lights, brightly colored and/or heavy concrete safety barriers, positioning of police vehicles nearby with their lights flashing, etc. Additionally, advisory signs are often positioned well ahead of the times when repair and/or construction work is to begin to provide advance notice to motorists who regularly travel through places where the repair and/or construction work is to be performed. Such measures are typically intended to encourage motorists to slow down as they drive through a portion of roadway at which a work site is located, and/or to watch more carefully and to be more prepared to respond to collision dangers that may arise. Unfortunately, despite such efforts, numerous incidents still occur each year in which impatient, inattentive and/or impaired motorists somehow do not see or respond appropriately to such warnings, thereby leading to vehicles barreling into roadway work sites. Although such measures as the placement of heavy concrete safety barriers are typically intended to provide some physical protection to construction workers from being hit by such a vehicle in such situations, the kinetic energy of a vehicle traveling on a roadway may very well overcome such protective efforts, especially on highways where vehicles typically travel at higher speeds.
Further, depending on the size of a roadway work site and/or other aspects of the repair and/or construction work to be done, the task of setting up warning signage and/or safety barriers can take considerable time and/or manpower away from the actual performance of the repair and/or construction work itself. By way of example, on a highway where motorists routinely drive vehicles at relatively high speeds, warning signage and/or safety barriers may need to be installed beginning as far as a mile or two ahead of the actual roadway work site. Providing such advance notice to motorists may require the transport and placement of relatively large quantities of warning signs, cones, barrels and/or concrete safety barriers, thereby requiring many vehicles in addition to considerable manpower.
It will be noted that in the above-referenced Provisional Application Ser. No. 62/638,818 filed Mar. 5, 2018 (which Provisional Application has already been incorporated herein by reference), the terms “cones” and “barrels” which are also mentioned in the present application (for example in the sentence just above) are referred to as “traffic delineators.”
Additionally, such extensive safety preparations may prove to be ill-suited to situations in which the repair and/or construction work that is performed is of a constantly and/or frequently moving or “rolling” nature. By way of example, the filling of potholes with asphalt, the replacement of lane-dividing reflectors built into roadway surfaces, and the painting of roadway lines often require a relatively small crew of construction personnel who move relatively slowly, but often continuously, along consecutive miles of roadway with only one or two construction vehicles as they perform their work. The initial placement and frequent subsequent movement of large sets of warning signs and/or safety barriers may actually entail more work requiring more resources than the repair and/or construction work that is being performed.
As an alternative to warning signage set up at fixed positions and/or the use of concrete safety barriers to provide protection, at least where the construction work that is performed is of such a rolling nature, trucks have sometimes been used that carry warning signage and/or a truck-mounted attenuator (TMA). The attachment of warning signage directly onto a truck enables far larger warning signs to be made more mobile, such that signs with larger display surfaces, and/or larger and more visible arrays of warning lights to be used. In particular, with regard to warning lights, truck mounted warning signs often have easier access to larger amounts of electric power to support the use of larger and/or brighter lighting components.
As is explained the referenced provisional applications, the terms “crash truck” and “safety truck” are often used interchangeably to refer to a relatively massive truck that has a TMA connected to a rear end region of the truck so as to extend rearwardly from the truck. The carrying of a TMA by a truck may allow a truck to serve as what may be referred to as a “crash truck” or “safety truck” in which that truck provides a more easily movable form of larger and heavier safety barrier than a concrete safety barrier thereby providing greater protection to construction personnel in situations where distracted, impatient and/or impaired motorists may still drive (i.e., “crash”) their cars or other vehicles into roadway work sites in spite of the presence of sufficient warning signage.
In this document, (and, as is familiar to those skilled in the arty, the abbreviation “TMA” will be understood to refer to an elongate structure that is typically mounted onto (or is otherwise “connected to”) the back (i.e., “a rear end region”) of a relatively massive roadway vehicle such as a “crash truck” or a “safety truck” so as to extend farther rearwardly from the truck to which the TMA is attached to thereby become the first component of the truck to which the TMA is attached that is physically encountered by a colliding roadway vehicle. TMAs, so positioned, are intended to become THE component of a so-called “crash truck” or “safety truck” that absorbs much, if not all, of the kinetic energy exerted on the truck as a result of an impact from a colliding vehicle. In essence, a TMA provides the truck with a sacrificial “crumple zone” that is intended to incur at least the majority of the damage that would otherwise be inflicted on the truck, itself, as a result of being collided with by another vehicle traveling at typical roadway speeds.
As will also be familiar to those skilled in the art, some of the best examples of TMAs currently available are designed to be crumpled in a controlled manner that spreads out the time during which an impact occurs to thereby reduce the magnitude of the forces exerted on a safety truck at any given moment in an effort to minimize the damage that is done to the truck. Also, such spreading out of the duration of the impact may aid in saving the lives of persons in the colliding vehicle. The most effective TMAs can reduce the severity of a collision occurring at highway speeds to a level somewhat on par with a collision occurring at speeds typically associated with residential roads.
Unfortunately, in spite of the use of such well-designed TMAs, the amount of kinetic energy imparted to a safety truck during an impact by a vehicle traveling at highway speeds may still cause the safety truck to be moved from its original position by a considerable distance. Thus, the provision of a safety truck with warning signage and a TMA does not represent a full and complete solution to the challenge of making safer the performance of repair and/or construction work at a roadway work site.